从第一层到第五层依次为:border、content+padding、background-image、background-color、margin。
2016-11-19
#wrap{width:970px;margin:0 auto;}
#mainbody{position:relative;margin-top:15px;}
#left{float:left;width:110px;border:1px solid #999; }
#mid{float:left;width:650px;border:1px solid #999;margin-left:13px;}
#right{position:absolute;margin-left:794px;border:1px solid #999;}
#mainbody{position:relative;margin-top:15px;}
#left{float:left;width:110px;border:1px solid #999; }
#mid{float:left;width:650px;border:1px solid #999;margin-left:13px;}
#right{position:absolute;margin-left:794px;border:1px solid #999;}
2016-11-17